Ropes are used for many applications that typically require one or both ends of a rope or multiple ropes to be secured in some manner. In such instances, the ropes are often secured by tying a knot or combination of knots. To address the wide range of variability in an even wider range of applications, many kinds of knots have been developed. There are few people who know how to tie sophisticated or complex knots. Lacking that knowledge, often what results when called to the task of tying knots are either knots inadequate to secure a load or knots that are difficult or impossible to untie.
Efforts to solve this dilemma have resulted in a variety of devices. Some of these devices completely circumvent the need for knots but typically are single function devices quite limited in application and often unable to adjust to varying load conditions. An example would be spring-loaded cinching devices for cords such as U.S. Pat. No. 6,038,746 to Anscher et al. (2000). These types of devices are targeted for use on stuff sacks, luggage, and outer wear; and they are not intended to be load-bearing devices. Other single function devices are rope tighteners such as U.S. Pat. No. 3,874,638 to Langlie et al. (1975) and lock-to-line devices such as U.S. Pat. No. 5,463,797 to Laug et al. (1995). These kinds of devices are niche devices targeted for very specific applications.
In rope securing devices that are intended as general usage load-bearing devices, some form of jam cleat, also known as a wedge cleat or boat cleat, often is used. Examples include U.S. Pat. No. 7,428,769 B2 to Fontaine, Maire (2008); U.S. Pat. No. 6,094,783 to Parsons (2000); U.S. Pat. No. 5,519,921 to Templer, Jr. (1996); and U.S. Pat. No. 4,719,668 to Cavanagh (1988). These items are designed for single rope usage or at best a loop device for a single rope, and require either access to the end of the rope on the non load-bearing side of the device or require removal of the load from the rope and the device in order to release the rope from the device.
Another technique often used for knot replacement is the “tortuous path” technique that usually involves a redirecting or rerouting of the rope through a device. Examples of this style would include U.S. Pat. No. 4,414,712 to Beggins (1983); U.S. Pat. No. 5,477,800 to Lawrence (1995); and U.S. Pat. No. 5,193,252 to Svehaug. Again, they require access to one end of the rope or require a fairly involved install process, are bulky in size, and often are intended to be left in place on a rope.
Other devices have been designed that attempt to incorporate more than one technique in terms of rope restraining features. Examples would be U.S. Pat. No. 2,450,358 to Romano (1945); and U.S. Pat. No. 7,464,443 B2 to Lopes Praca (2008). These devices can be awkward, bulky, or can even catch or snag on surrounding elements and, hence, are not suited for storage with the line such as in the case of a rolled up rain fly or back packing tent.
None of the devices truly replicate the multiplicity in function or the compactness in size afforded through the use of knots.